DS1283 Datasheet, PDF (1/5 Pages) Dallas Semiconductor – Watchdog Timekeeper Chip

DS1283
DS1283
Watchdog Timekeeper Chip
FEATURES
• Keeps track of hundredths of seconds, seconds, min-
utes, hours, days, date of the month, months, and
years; valid leap year compersation up to 2100
• Watchdog timer restarts an out–of–control processor
• Alarm function provides notice of real time related oc-
currences
• Designed for battery operation
• Programmable interrupts and square wave outputs
maintain 28–pin JEDEC footprint
• All registers are individually addressable via the ad-
dress and data bus
• Accuracy is better than ±2 minutes/month at 25°C
• 50 bytes of user nonvolatile RAM
• Optional 28–pin SOIC surface mount package
• Low–power CMOS circuitry is maintained on less
than 1 µA in standby mode
• Optional industrial temperature range –40°C to +85°C
DESCRIPTION
The DS1283 Watchdog Timekeeper Chip is a self–con-
tained real time clock, alarm, watchdog timer, and inter-
val timer in a 28–pin JEDEC DIP or 28–pin SOIC sur-
face mount package. The DS1283 is specifically
designed to maintain internal operations from a single
low voltage supply. In fact, the only two external compo-
nents required by the DS1283 are a battery and crystal.
For a complete description of operating conditions,
electrical characteristics, bus timing, and pin descrip-
tions other than X1, X2, V_BAT, V_CC, RCLR, INTB, and
INTP see the DS1286 Watchdog Timekeeper data
sheet.
PIN ASSIGNMENT
INTA 1
X1 2
X2 3
NC 4
A5 5
28
VCC
27 ^WE
26
INTB(INTB)
25
VBAT
24 ^RCLR
A4 ₆
23 ^SQW
A3
A2
A1
A0
DQ0
DQ1
DQ2
GND
7
22 ^OE
8
21 INTP
9
20 ^CE
10
19 ^DQ7
11
18 ^DQ6
12
17 ^DQ5
13
16 ^DQ4
14
15 ^DQ3
DS1283
28–PIN DIP (600 MIL)
INTA
1
X1
2
X2
3
NC
4
A5
5
A4
6
A3
7
A2
8
A1
9
A0
10
DQ0
11
DQ1
12
DQ2
13
28
V _CC
27
WE
26
INTB(INTB)
25
VBAT
24
RCLR
23
SQW
22
OE
21
INTP
20
CE
19
DQ7
18
DQ6
17
DQ5
16
DQ4
GND
14
15
DQ3
DS1283S
28–PIN SOIC (330 MIL)
NOTE: Pin 4 must be left disconnected.
ECopyright 1997 by Dallas Semiconductor Corporation.
All Rights Reserved. For important information regarding
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